The city referendum process is governed by the Oregon Constitution, Oregon Revised Statutes, Portland City Charter and Portland City Code.

Article IV, Section 1 of the Oregon Constitution, Section 3-201 of the Portland City Charter, and Section 2.04.040 of the City Code give citizens of the City of Portland the ability to refer City legislation to a vote of the people through the referendum petition process.

The referendum petition process provides citizens with a vehicle to refer an Ordinance passed by Council to a vote of the people. Petitioners must file their petitions for signature verification within 30 days of the Council action. An ordinance filed with an emergency clause may not be referred. Non-emergency ordinances become effective 30 days after passage. Franchise petitions shall be filed within 60 days of the date of passage. According to City Charter Sections 2-123 and 10-208, a referendum petition suspends the effective date of an ordinance.